1. Field of the Invention
The present invention relates to a steering apparatus for a ship propeller.
2. Description of the Related Art
In a steering apparatus for a ship propeller, as described in Japanese Patent Application Laid-open No. 5-221385 (patent document 1), there is a steering apparatus for a ship propeller structured such that a steering handle is provided within a ship body. A propelling unit is fixed to a steering shaft rotatably supported to an attaching bracket fixed to the ship body, and a steering cable connected to the steering handle is coupled to a steering arm fixed to the steering shaft, in which a hydraulic cylinder unit is connected to the steering arm. A working fluid pressure fed by a hydraulic pump driven by an electric motor is supplied to the hydraulic cylinder, thereby assisting steering force applied to the steering handle by a driver.
In the steering apparatus for the ship propeller described in the patent document 1, it is necessary that the hydraulic cylinder unit is provided together with the electric motor and the hydraulic pump near the propelling unit. Accordingly, a large space is required, and a hydraulic circuit is also required in addition to a feeding circuit, which results in a complicated structure. Further, since a pressure receiving area is different between right and left sides of the hydraulic cylinder, it is necessary to correct the rotational speed of the electric motor when turning to the right and the left.